Multiple layer optical disc, and device for writing such disc

ABSTRACT

A method of operating a medium access device includes writing by a writer information in a logical storage space of a storage medium which has a physical storage space comprising two or more layers of physical storage locations, each storage location having a physical address, the logical storage space comprising storage locations within a first layer of the layers and within a subsequent layer of the layers, the storage locations in the logical storage space having contiguously numbered logical addresses; storing in an address limit memory at least a value for a parameter indicating a maximum value of the logical addresses of the storage locations in the first layer; and changing by a processor the maximum value in the address limit memory and to provide an output when the maximum value cannot be changed to avoid attempting changing the maximum value.

This application claims the benefit or priority of and describesrelationships between the following applications: wherein thisapplication is a continuation of U.S. patent application Ser. No.14/061,863, filed Oct. 24, 2013, which is a continuation of U.S. patentapplication Ser. No. 10/575,002, filed Apr. 6, 2006, now U.S. Pat. No.8,601,208, granted on Dec. 3, 2013, which is the National Stage ofInternational Application No. PCT/IB2004/051866, filed Sep. 27, 2004,which claims the priority of foreign application EP 03103700.5 filedOct. 6, 2003, all of which are incorporated herein in whole byreference.

The present invention relates in general to a multiple layer opticalstorage disc, and to a method and device for writing information intosuch disc.

As is commonly known, an optical storage disc comprises at least onetrack, either in the form of a continuous spiral or in the form ofmultiple concentric circles, of storage space where information may bestored in the form of a data pattern. Optical discs are very successful,and several different types have been developed. One such type is DVD(Digital Versatile Disc), and the present invention relates particularlyto DVD discs, more particularly to DVD-Video, for which reason thepresent invention will be explained in the following for DVD-Videodiscs. However, the gist of the present invention is also applicable toother types of recordable discs; therefore, the following description isnot to be understood as limiting the scope of the present invention toDVD discs only.

Optical discs may be read-only type, where information is recordedduring manufacturing, which information can only be read by a user. Theoptical storage disc may also be a writeable type, where information maybe stored by a user. Such discs may be a write-once type, indicated aswritable (R), but there are also storage discs where information can bewritten many times, indicated as rewritable (RW). In the case of DVD, adistinction is made between two formats, i.e. DVD-RW and DVD+RW.

For writing information in the storage space of the optical storagedisc, the storage track is scanned by an optical write beam, typically alaser beam, of which the intensity is modulated to cause materialchanges which can later be read out by scanning the storage track by anoptical read beam. Since the technology of optical discs in general, andthe way in which information can be stored in an optical disc, iscommonly known, it is not necessary here to describe this technology inmore detail.

As is commonly known, memory space of an optical disc is divided intoblocks, each block having an identification or address, such that awriting apparatus can access a certain block to write data at apredefined location. In the case of RW-type discs, the storage space isphysically present in the form of a groove (+RW) or pre-pits (−RW), theblocks are predefined, and the addresses are already allocated and codedin physical hardware features of the storage space. These addresses willbe indicated as physical addresses. The combination of all physicaladdresses will also be indicated as physical storage space.

Typically, an optical storage system comprises an optical disc as arecord medium, and further comprises a disc drive apparatus and a hostapparatus. The disc drive apparatus is a device, comprising opticalmeans for actually writing data, capable of accessing storage blocks atthe level of physical addresses. Thus, in principle, the entire physicalstorage space is accessible to the disc drive apparatus. The hostapparatus, which may be a PC running a suitable program, or anapplication of a consumer apparatus such as a video recorder, is adevice which communicates with the disc drive, and sends commands to thedisc drive instructing the disc drive to write certain data to a certainstorage location. In contrast to the disc drive apparatus, the hostapparatus only has access to a part of the physical storage space, thispart being indicated as logical storage space, and the storage blocks inthe logical storage space also have logical storage addresses. Althoughthe logical storage space does not need to be a physically contiguousstorage space, the storage blocks in the logical storage space haveconsecutive logical addresses, which are usually not identical to thephysical addresses.

The host apparatus only has access to storage blocks at the level oflogical addresses. Actually, it is perhaps not entirely correct to saythat the host apparatus can access storage blocks; after all, the hostapparatus can not access storage blocks directly, but only through theintermediary of the disc drive apparatus. The host apparatus requeststhe disc drive apparatus to access (write or read) a certain logicaladdress. The disc drive apparatus, which has information regarding therelation between logical addresses and physical addresses, makes atranslation to the required physical address, and accesses thecorresponding block at the level of the physical address.

Conventionally, an optical disc has only one storage layer containing astorage track. More recently, optical discs have been developed havingtwo or even more storage layers, each storage layer containing a storagetrack in the shape of a spiral or multiple concentric circles. In suchcase, the logical storage space extends over multiple storage layers,hence the range of logical addresses extends contiguously over multiplestorage layers. The transition from the last block of one storage layerto the first block of the next storage layer is such that the logicaladdress is incremented only by 1.

A typical problem occurs in the case of a DVD-Video Disc. According tothe DVD Video Standard, it is (as a rule) not possible to continuewriting right through to the last possible block of the first layer, andthen to make a transition to the first block of the next layer. Duringwriting, DVD Video data is organized in cells, and a transition from onelayer to the next is only allowed at a cell boundary. This is related tothe fact that, on reading video data from disc, it is desirable to haveseamless continuation of video image display. Since it is usually notknown in advance where these cell boundaries will be located, it is notknown in advance where the transition from one layer to the next will bemade. Consequently, it is not known in advance what the highest logicaladdress of one storage layer is; likewise, it is not known in advancewhat the relation is between physical addresses and logical addresses inthe next layer.

As a consequence, during writing, it is difficult to determine thestorage capacity of the remaining disc.

Further, before being able to write in the second layer, a preparationprocess indicated as Optimal Power Calibration (OPC) is to be performed,which is performed in a dedicated area indicated as OPC area. It is mostefficient if this OPC area is located as close as possible to the areawhere the transition from first layer to second layer is made. Further,it is most efficient if this OPC procedure can be performed in advance.If it is not known in advance where such transition area is located, theOPC area can only be created at the moment when the transition is totake place, and also the OPC procedure can take place only then, whichis disadvantageous because such procedure takes time.

In the case of a dual layer disc, the structure of the first layer isdescribed in the DVD-standard: numbering of the logical addresses startsat physical address 30000, and increases from smaller radius to largerradius. For the next layer, there are two possibilities. In onepossibility, indicated as Parallel Track Path (PTP), the logicaladdresses are numbered from the inner track radius to the outer trackradius, too. In another possibility, indicated as Opposite Track Path(OTP), the logical addresses are numbered from the outer track radius tothe inner track radius. In a PTP case, after a jump from the first trackto the next, writing continues at the innermost track of the availablestorage space; in such case, the storage capacity of the next track isindependent from the location of the last block of the first track. Inan OTP case, however, after a jump from the first track to the next,writing continues at the location of the jump; in such case, the size ofthe available logical space in the next track is clearly dependent onthe location of the last block of the first track.

In practice, a disc drive does not continue writing till the very lastphysical address of a storage layer before jumping to the next storagelayer. Instead, the disc drive has a parameter which will be indicatedhereinafter as LAmax, and which indicates a maximum value for thelogical addresses of a layer. When, on writing, the disc drive reachesthe block with logical address LAmax, a jump is made to the next storagelayer. Usually, this is not the most suitable location with a view tovideo cell boundaries, but the disc drive itself has no means fordetermining or calculating such boundaries. In contrast, the host deviceis capable of determining video cell boundaries, but the host device isonly capable of determining logical addresses; more particularly, thehost device is not capable of instructing the disc drive to use aspecific physical address, and is not capable of instructing the discdrive to go to a next storage layer.

An important objective of the present invention is to overcome the abovedifficulties.

More specifically, an objective of the present invention is to assurethat the last logical address of a storage layer corresponds to a videocell boundary, in order to assure seamless image reproduction onreading.

In the above, objectives of the present invention have been explained inthe context of video cell boundaries in the case of writing video data.However, it may be desirable for other reasons to be able to adjust thesize of the logical space of a storage layer, i.e. the number of logicaladdresses in a storage layer. Therefore, a general objective of thepresent invention is to be able to vary the size of the logical space ofa storage layer.

According to an important aspect of the present invention, a disc driveis capable of changing the value LAmax. A host is capable determining acell boundary, and to calculate a suitable value for LAmax, and to senda command to the disc drive, effectively instructing the disc drive totake the calculated value for LAmax. In response, the disc drive storesthis value in a memory location.

These and other aspects, features and advantages of the presentinvention will be further explained by the following description withreference to the drawings, in which same reference numerals indicatesame or similar parts, and in which:

FIG. 1 is a block diagram schematically illustrating a data storagesystem;

FIG. 2A is a diagram schematically depicting a double-track storagespace of a storage medium in a PTP case;

FIG. 2B is a diagram schematically depicting a double-track storagespace of a storage medium in an OTP case;

FIG. 2C is a diagram schematically depicting a logical storage space;

FIG. 3 is a diagram schematically depicting a logical storage space aswell as a video sequence;

FIG. 4 is a diagram schematically depicting a logical storage space aswell as a video sequence;

FIG. 5 is a flow diagram schematically illustrating steps of a writemethod in accordance with the present invention;

FIG. 6 is a table illustrating a RESERVE TRACK command suitable for usein a write method in accordance with the present invention;

FIG. 7 is a table illustrating a WRITE PARAMETERS MODE PAGE commandsuitable for use in a write method in accordance with the presentinvention;

FIG. 8 is a table illustrating a SEND DVD STRUCTURE command suitable foruse in a write method in accordance with the present invention;

FIG. 9 is a table illustrating a format field of a SEND DVD STRUCTUREcommand;

FIG. 10 is a table illustrating a READ DVD STRUCTURE command;

FIG. 11 is a table illustrating READ DVD STRUCTURE data.

FIG. 1 is a block diagram schematically illustrating a data storagesystem 1, comprising a data storage medium 2, a medium access device 10,and a host device 20. In a typical practical implementation, the hostdevice 20 may be a suitably programmed personal computer (PC); it isalso possible that the data storage system 1 is implemented as adedicated user apparatus such as a video recorder, in which case thehost device 20 is the application part of such apparatus. In a specificembodiment, the data storage medium 2 is implemented as an optical disc,specifically a DVD, more specifically a DVD+R, in which case the mediumaccess device 10 is implemented as a disc drive. In the following, theinvention will be described specifically for an optical discimplementation, but it is noted that the present invention is notlimited to optical discs.

The optical disc 2 has a storage space 3, which has the form of two ormore continuous spiral-shaped tracks or track in the form of multipleconcentric circles, where information can be stored in the form of adata pattern. Since this technology is commonly known to persons skilledin the art, this technology will not be explained in further detail.

The several tracks of the storage space 3 are located in differentstorage layers of the optical disc 2, which storage layers will beindicated L0, L1, etc. FIG. 2A is a diagram schematically depicting thestorage space 3 as a collection of long ribbons, each ribboncorresponding to a storage layer L0, L1, for a case where the opticaldisc 2 has two storage layers. The storage space 3 is divided into alarge number of blocks 4. Each block has a physical address, which willhereinafter be indicated as PA. In FIG. 2A, the physical addresses PAare indicated underneath the blocks 4: in each storage layer L0, L1, thenumbering of the physical addresses starts at zero (left-most block inFIG. 2A). Each following block has an address which is one higher thenits previous neighbour. The last block has the highest address P0, P1.In case the two storage layers L0 and L1 have equal size, P0=P1.

Most blocks also have a logical address, which will hereinafter beindicated as LA; in FIG. 2A, logical addresses are indicated above theblocks 4. It can be seen that numbering starts at LA=0 for a certainblock in L0, which typically is the block with PA=30000.

The highest logical address in L0 is indicated as N; it can be seen thatthis is not necessarily the last block of L0.

The lowest logical address in the next storage layer L1 is LA=N+1, for acertain block in L1, which is not necessarily the first block;typically, this is the block with PA=30000 in L1, i.e. the same physicaladdress as the first logical address LA=0 in the first storage layer L0,but this is not essential.

The highest logical address is indicated as N; it can be seen that thisdoes not necessarily corresponds to the last block of L1.

In the first logical layer L0, when comparing two blocks, the one withthe highest logical address also has the highest physical address. InFIG. 2A, the same applies to the second storage layer L1; suchconfiguration is indicated as Parallel Track Path (PTP). FIG. 2B is adiagram comparable to FIG. 2A, for a case of an Opposite Track Path(OTP) configuration, in which case increasing logical addressescorresponds to decreasing physical addresses. In that case, the radiallocation of block LA=N in L0 corresponds to the radial location of blockLA=N+1 in L1, as indicated.

The blocks having a logical address together define the logical storagespace (LSS). FIG. 2C is a diagram schematically depicting the LSS as onelong continuous ribbon. In the LSS, the addresses range from zero to M.When the host device 20 wants to access a certain piece of information,it sends a request to the disc drive 10, indicating the correspondinglogical address. The disc drive 10 comprises a memory 11, which containsinformation regarding the relationship between logical addresses LA andphysical addresses PA, for instance in the form of a look-up table.Based on this information, the disc drive 10 determines which storagelayer and which physical address correspond to the required logicaladdress.

FIG. 3 is a diagram comparable to FIG. 2C, showing the LSS, and alsoshowing schematically a video sequence 30, for instance corresponding toa movie, also illustrated as a ribbon, which extends from a location inL0 to a location in L1. The video sequence 30 has a start 31 and an end39. The data of the video sequence 30 define video cells 35; cellboundaries between the video cells 35 are indicated at 34. With respectto “video cells”, reference is made to part III of the DVD videospecification.

In FIG. 1, a host/drive communication link between host device 20 anddisc drive 10 is indicated at 5. Likewise, a drive/disc communicationlink between disc drive 10 and disc 2 is indicated at 6. The drive/disccommunication link 6 represents the physical (optical) read/writeoperation as well as the physical addressing of blocks 4 of the storagespace 3. The host/drive communication link 5 represents a data transferpath as well as a command transfer path.

Assume that a data storage system 1, not implemented in accordance tothe present invention, is to store the video sequence 30. The hostdevice 20 transfers the video sequence 30 to the disc drive 10 overhost/drive communication link 5, and the disc drive 10 writes the videosequence 30 to disc 2 over drive/disc communication link 6, wherein thestart 31 of the video sequence 30 is written at a block in L0 having acertain logical address LA START which may be determined by the hostdevice 20, or which may be the first available block after a previousrecording.

The disc drive 10 has an address limit memory 12, containing a defaultvalue for a parameter LAmax indicating the maximum value of the logicaladdresses in the first storage layer L0. The disc drive 10 is designedto compare the logical addresses of the blocks accessed with the valueof LAmax in its address limit memory 12. As writing continues, thelogical addresses increase. If the block is reached for which LA=LAmax,the disc drive 10 makes a transition to the first available block in thenext storage layer L1, which now obtains logical address LA=LAmax+1. Itcan be seen in FIG. 3 that this transition corresponds to a locationsomewhere within a video cell 35.

FIG. 4 is a diagram comparable to FIG. 3, now for the case of a datastorage system 1 implemented in accordance with the present invention.FIG. 5 is a flow diagram, schematically illustrating steps of theoperation 200 of the host device 20 and the operation 100 of the discdrive 10 when performing a write method in accordance with the presentinvention.

The host device 20 sends video data to the disc drive 10 [step 211]. Thedisc drive 10 receives these data [step 131] and writes the datareceived to disc 2 [step 132]. After having completed a block [step151], the disc drive 10 compares the logical address LA of the currentblock with the value of LAmax in its address limit memory 12 [step 152].If the upper limit LAmax has been reached, the disc drive makes atransition [step 153] to the first available block in the next storagelayer L1, otherwise this transition step is skipped. In respect of thenext available block, the logical address LA is increased by one [step161], and this address is communicated to the host device [step 162].Then, operation of the disc drive returns to step 131.

The host device 20 receives the logical address LA as communicated bythe disc drive 10 [step 212]. This information allows the host device 20to keep track of the recording location of the video data, if desired.

The host device 20 is capable to evaluate the video data to be written,and is thus capable to determine where cell boundaries are to beexpected [step 221].

According to an important aspect of the present invention, the hostdevice 20 determines whether it should fix a value for the last logicaladdress in L0 [step 222]. For instance, it may be that the host device20 finds that only a small number of cells fit into the remaining partof L0. If the host device 20 decides to fix a value for the last logicaladdress in L0, it determines a value LAmax [step 223], and it sends[step 224] a special command to the disc drive 10, which willhereinafter be indicated as Limit Fix Command LFC. Then, operation ofthe host device returns to step 211.

In the step of determining a value LAmax, the host device 20 takes intoconsideration the cell boundaries as determined in step 221.Particularly, the host device 20 determines the value LAmax such thatthe block having address LA=LAmax receives the last block of a videocell.

The disc drive 10 checks whether it receives the Limit Fix Command LFC[step 141]. If it does, it derives LAmax from the Limit Fix Command LFC[step 142], and it stores this value into its address limit memory 12[step 143].

Consequently, when later the block having address LA=LAmax is written,it receives the last block of a video cell, and the first availableblock in the next storage layer L1 receives the first block of a nextvideo cell, so that the transition from the first storage layer L0 tothe next storage layer L1 corresponds to a video cell boundary 34, asillustrated in FIG. 4.

The information contained in the Limit Fix Command LFC should be such asto enable the disc drive 10 to derive LAmax. It is possible that theLimit Fix Command LFC contains the value of LAmax itself, or anothernumber directly related to LAmax, which is specifically suitable incases where it is desirable to align storage blocks 4 with video cellboundaries 34. However, it is also possible that it is desirable tosimply fix the maximally available size of the storage space 3, forinstance to adapt this maximum to a video recording to be written. Insuch case, it might be suitable to send information defining a value forM, in which case the disc drive 10 may derive LAmax from the informationreceived, either by division by 2 (suitable in the case of OTP) or bysubtracting the full size of the second storage layer L1 (suitable inthe case of PTP).

In a preferred embodiment, also illustrated in FIG. 5, the disc drive 10is designed to also write LAmax to a predetermined location on disc[step 144], which location may be located in a part of the storage space3 reserved for use by the disc drive. This offers the advantage that itis possible to fix LAmax for a certain disc, which value of LAmax isalso respected by other disc drives. To this end, it is furtherpreferred that the disc drive 10 is adapted, on receiving a new disc 2,to read the said predetermined location of the disc [step 121] and tostore the read value into the address limit memory 12 [step 122], asalso illustrated in FIG. 5. If the disc does not have a value for LAmaxwritten in said predetermined location, the disc drive 10 maintains thedefault setting for LAmax.

The disc drive 10 may read the information of said predeterminedlocation of the disc on its own initiative, or on receiving a Disc ReadCommand from the host 20, or both. In the embodiment illustrated in FIG.5, the host 20 is adapted to first send a Disc Read Command to the discdrive [step 201]. The disc drive 10 receives the Disc Read Command [step120], and, in response, it reads the said predetermined location of thedisc [step 121], and sends to the host 20 a Disc Read Responsecontaining information relating to LAmax [step 123]. The host 20receives [step 202] this information, which may be a value identical toLAmax or a value from which LAmax can be derived. If the disc does nothave a value for LAmax written in said predetermined location, the discdrive 10 may send the default address, but it is also possible that thedisc drive sends a code, for instance address=zero, indicating thatLAmax has not been fixed yet.

The information in the Disc Read Response received from the disc drive10 is used by the host 20, in step 222, when the host 20 determineswhether or not it should fix a value for the last logical address in L0.If the information in the Disc Read Response indicates that the host 20is free to amend LAmax, operation of steps 221-224 continues asdescribed above. However, if the information in the Disc Read Responseindicates that it is not possible to amend LAmax, for instance becauseLAmax has already been fixed previously, the host 20 will always exitstep 222 at the NO exit, effectively skipping steps 223-224; or, thehost 20 may even skip step 222.

There are several practical possibilities envisaged for implementing theLimit Fix Command LFC. First, it is of course possible to define anentirely new command. However, it is easier to adapt existing commandsof an existing command set. An example of a widely used command set isindicated as MMC3, also indicated as “Mount Fuji” (see, for instance,ww.t10.org: “Multimedia Command Set Version 3 Revision 10G”). In thefollowing, several examples of suitable existing commands will bedescribed.

EXAMPLE 1 Reserve Track (RT)

As illustrated by the table in FIG. 6, the RT command comprises 10 bytesof 8 bits each. Bytes 1 to 4 are reserved for later definition, i.e.they do not have a defined meaning yet. So, it is possible to use anyone of the bits of these bytes as “Define LAmax” bit DL, indicating thatthe RT command is to be taken as a Limit Fix Command LFC. For instance,as indicated, the value of bit 0 of byte 1 may indicate RT=LFC. Bytes 5to 8 contain “reservation size”, wherein byte 8 is the least significantbyte while byte 5 is the most significant byte. In the case that the RTcommand is used as Limit Fix Command LFC, these bytes 5 to 8 may containa value indicating LAmax.

EXAMPLE 2 Write Parameters Page (WPP)

As illustrated by the table in FIG. 7, the WPP command comprises 56bytes of 8 bits each. Bytes 32 to 47 contain “International Standardrecording Code”, which does not hold for DVD, therefore these bytescould contain a value indicating LAmax. Several bytes are reserved forlater definition, i.e. they do not have a defined meaning yet, forinstance bit 6 of byte 0, bits 4-7 of byte 4, byte 6, bits 6-7 of byte7, byte 9. So, it is possible to use any one of these bits as “DefineLAmax” bit DL, indicating that the WPP command is to be taken as a LimitFix Command LFC. For instance, as indicated, the value of bit 6 of byte0 may indicate WPP=LFC.

EXAMPLE 3 Send DVD Structure (SDS)

As illustrated by the table in FIG. 8, the SDS command comprises 17bytes of 8 bits each. Bytes 1 to 6 are reserved for later definition,i.e. they do not have a defined meaning yet. So, it is possible to useany one of these bits as “Define LAmax” bit DL, indicating that the SDScommand is to be taken as a Limit Fix Command LFC, in which case bytes8-9, which contain “structure data length”, may contain a valueindicating LAmax.

It is also possible to use byte 7, which contains a “format code”, itsvalue containing a definition for the meaning of the following bytes.The table in FIG. 9 illustrates the current definition of the formatfield. Value 20 h for byte 7 may for instance be used to indicate thatthe SDS command contains 17 bytes, and that bytes 14-16 contain a valueindicating LAmax.

There are also several practical possibilities envisaged forimplementing the Read Disc Command A suitable existing command is theread dvd structure command.

EXAMPLE 4 Read DVD Structure (RDS)

As illustrated by the table in FIG. 10, the RDS command comprises 12bytes of 8 bits each. Byte 7 contains a format code, which indicates themeaning of the RDS command; Bytes 2-5 contain address information as aparameter to this RDS command, which parameter is not necessary in thecase of a Read Disc Command since the disc drive 10 will know at whichaddress to look. For instance, value 20 h for the format code might beused to indicate that the RDS command is to be taken as a Read DiscCommand.

FIG. 11 is a table illustrating a possible Disc Read Response whichmight be sent by the disc drive 10 to the host 20. The Read DVDStructure Data format comprises a field having the name “DVD Lead-inStructure”, containing 5 bytes of 8 bits each. For instance, byte 2-4 ofthis field may be used to indicate the logical address of the last usersector in the first layer L0. This may be done by directly giving thevalue of LAmax, but it is also possible, for instance, to give thephysical address of the last user sector in the first layer L0, fromwhich LAmax can be derived.

It should be clear to a person skilled in the art that the presentinvention is not limited to the exemplary embodiments discussed above,but that several variations and modifications are possible within theprotective scope of the invention as defined in the appending claims.

For instance, the above-mentioned examples do not involve an exhaustivelisting; it is possible to use other existing commands for instructing adisc drive to fix an upper value for the logical addresses in a storagelayer, but, at least currently, the examples mentioned are preferred.

Further, instead of sending the limit fix command as embedded in videodata, it is also possible that the host device 20 sends the limit fixcommand independent from video data.

In the above, the invention has been explained for the case of a dischaving two storage layers. However, the gist of the present invention isalso applicable in the case of multiple layers. In a limit fix command,the host may include the identity of the layer for which the limit is tobe fixed, but it is also possible that the limit fix command is alwaysinterpreted as applying to the layer currently be written.

It may be possible that the host sends the limit fix command when it istransferring the last video cell that will fit in the current layer.However, it is also possible that the host is capable of determiningwhere the cell boundaries are a long time in advance, so that the limitfix command may be sent a long time before transferral of the last videocell.

In the above, the present invention has been explained with reference toblock diagrams, which illustrate functional blocks of the deviceaccording to the present invention. It is to be understood that one ormore of these functional blocks may be implemented in hardware, wherethe function of such functional block is performed by individualhardware components, but it is also possible that one or more of thesefunctional blocks are implemented in software, so that the function ofsuch functional block is performed by one or more program lines of acomputer program or a programmable device such as a microprocessor,microcontroller, digital signal processor, etc.

The invention claimed is:
 1. A method of operating a medium accessdevice comprising acts of: writing by a writer information in a logicalstorage space of a storage medium which has a physical storage spacecomprising two or more layers of physical storage locations, eachstorage location having a physical address, the logical storage spacecomprising storage locations within a first layer of the layers andwithin a subsequent layer of the layers, the storage locations in thelogical storage space having contiguously numbered logical addresses;storing in an address limit memory at least a value for a parameterindicating a maximum value of the logical addresses of the storagelocations in the the first layer; and changing by a processor themaximum value in the address limit memory and to provide an output whenthe maximum value cannot be changed to avoid attempting changing themaximum value.
 2. The method of claim 1, further comprising acts of:comparing the logical address of the current block with the maximumvalue stored in the address limit memory while writing in the firstlayer; and making a transition to the first available block in thesubsequent layer when a result of the comparing act shows that themaximum value has been reached for the first layer.
 3. The method ofclaim 1, further comprising acts of: storrin the maximum value in theaddress limit memory; and writing the maximum value to a predeterminedstorage location of the storage medium.
 4. A method of operating amedium access device comprising acts of: writing by a writer informationin a logical storage space of a storage medium having two or more layersof physical storage locations, each storage location having a physicaladdress, the physical storage space comprising a logical storage spacewhich contains storage locations within a first layer of the layers andwithin a subsequent layer of the layers, the storage locations in thelogical storage space having contiguously numbered logical addresses;the storage medium having at least one predetermined storage locationfor containing a value for a parameter indicating a maximum value of thelogical addresses of the storage locations in the the first layer;reading by a processor the maximum value from the predetermined storagelocation; storing the maximum value in an address limit memory of themedium access device to change the maximum value so that a transitionfrom the first layer to the subsequent layer corresponds to a video cellboundary; and providing an output when the maximum value cannot bechanged to avoid attempting changing the maximum value.
 5. The method ofclaim 4, further comprising an act of reading the maximum value from thepredetermined storage location in response to connection of the storagemedium to the medium access device.
 6. A method of operating a datastorage system comprising acts of: providing a writeable storage mediumhaving a physical storage space comprising two or more layers ofphysical storage locations, each storage location having a physicaladdress, the physical storage space comprising a logical storage spacewhich contains storage locations within a first layer of the layers andwithin a subsequent layer of the layers, the storage locations in thelogical storage space having contiguously numbered logical addresses;providing a medium access device configured to write information in alogical storage space of the writeable storage medium the medium accessdevice having an address limit memory containing at least a value for aparameter indicating a maximum value of the logical addresses of thestorage locations in the the first layer; the medium access devicechanging the value in the address limit memory; providing a host deviceconfigured to cooperate with the medium access device to determine adesired maximum value so that a transition from the first storage layerto a next storage layer corresponds to a video cell boundary; sending acommand to the medium access device including one of the desired maximumvalue and a further value used for deriving the desired maximum value bythe medium access device; and providing by the medium access device tothe host device an indication when the maximum value cannot be changedand the in response to the indication so that the host device avoidssending the limit fix command.
 7. The method of claim 6, wherein thestorage medium has at least one predetermined storage location forcontaining the maximum value of the logical addresses of the storagelocations in the the first storage layer, the method further comprisingacts of: reading by the medium access device the value for the parameterfrom the predetermined storage location; and storing the value in theaddress limit memory.
 8. A method of controlling an optical drive by ahost device, the optical drive being capable of writing information inblocks of a logical storage space (LSS) of an optical disc which has aphysical storage space comprising two or more layers (LO; LI) ofphysical storage locations, each storage location having a physicaladdress (PA), the logical storage space (LSS) comprising storagelocations within a first storage layer (LO) of the layers and within asubsequent storage layer (LI) of the layers, the storage locations inthe logical storage space (LSS) having contiguously numbered logicaladdresses (LA), the method comprising acts of: providing data from thehost device to the optical drive, the data containing information to bewritten onto the optical disc and/or data containing instructions forthe optical drive, the optical drive having an address limit memorycontaining at least an indication of a parameter LAmax indicating amaximum value of the logical addresses (LA) of the storage locations inthe first storage layer (LO); providing from the host device to theoptical drive a limit fix command instructing the optical drive to storethe indication of the parameter LAmax as determined by the host devicein the address limit memory; changing by the optical drive theindication of the parameter LAmax in the address limit memory to theindication provided by the host device; sending a Disc Read Command fromthe host device to the optical drive; receiving by the host device aDisc Read Response from the optical drive indicating whether or not theparameter LAmax is changeable; and avoiding providing by the host devicethe limit fix command in response to the act of receiving a Disc ReadResponse from the optical drive indicating that the parameter LAmaxcannot be changed.
 9. The method of claim 8, further comprising acts of:comparing by oprical drive the logical addresses (LA) of a current blockwith a value of the parameter LAmax stored in the address limit memorywhile writing in the first storage layer (LO); and making a transitionto a first available block in the subsequent storage layer (LI) when aresult of the comparing act shows that the value of the parameter LAmaxhas been reached for the first storage layer (LO).
 10. The method ofclaim 9, further comprising acts of: storing the value of the parameterLAmax in the address limit memory of the optical drive; and writing thevalue of the parameter LAmax to a predetermined storage location of theoptical disc.
 11. The method of claim 10, further comprising acts of:writing information in the logical storage space (LSS) of the opticaldisc; reading by the oprical drive the value for the parameter LAmaxfrom the predetermined storage location; and storing by the opricaldrive the value for the parameter LAmax in its address limit memory. 12.A method of operating a host device for controlling an optical drivecapable of writing information in a logical storage space (LSS) of anoptical disc which has a physical storage space comprising two or morelayers (LO; LI) of physical storage locations, each storage locationhaving a physical address (PA), the logical storage space (LSS)comprising storage locations within a first one (LO) of the layers andwithin a subsequent one (LI) of the layers, the storage locations in thelogical storage space (LSS) having contiguously numbered logicaladdresses (LA), the method comprising acts of: providing by the hostdevice to the optical drive data containing information to be writtenonto the optical disc and/or data containing instructions for theoptical drive, the optical drive having an address limit memorycontaining at least an indication of a parameter LAmax indicating amaximum value of the logical addresses (LA) of the storage locations inthe the first storage layer (LO); determining by the host device whetherthe the indication of the parameter LAmax stored in the address limitmemory of the optical drive is changeable; and sending by the hostdevice to the optical drive a limit fix command instructing the opticaldrive to change the indication of the parameter LAmax as determined bythe host device in the address limit memory based on a result of thedetermining act, wherein the sending act is avoided in response toreceiving from the optical drive an indication that the parameter LAmaxcannot be changed.
 13. The method of claim 12, wherein the indicationthat the parameter LAmax cannot be changed is provided by the opticaldrive in a Disc Read Response in response to receivign a Disc ReadCommand from the host device.
 14. A method of operating an opticaldrive, the optical drive being capable of writing information in blocksof a logical storage space (LSS) of an optical disc which has a physicalstorage space comprising two or more layers (LO; LI) of physical storagelocations, each storage location having a physical address (PA), thelogical storage space (LSS) comprising storage locations within a firststorage layer (LO) of the layers and within a subsequent storage layer(LI) of the layers, the storage locations in the logical storage space(LSS) having contiguously numbered logical addresses (LA), the methodcomprising acts of: receiving data from a host device, the datacontaining information to be written onto the optical disc and/or datacontaining instructions for the optical drive, the optical drive havingan address limit memory containing at least an indication of a parameterLAmax indicating a maximum value of the logical addresses (LA) of thestorage locations in the first storage layer (LO); receiving from thehost device a limit fix command instructing the optical drive to storethe indication of the parameter LAmax as determined by the host devicein the address limit memory; changing by the optical drive theindication of the parameter LAmax in the address limit memory to theindication provided by the host device; sending a Disc Read Command bythe host device to the optical drive; receiving by the host device aDisc Read Response from the optical drive indicating whether or not theparameter LAmax is changeable so that the host device avoids sending thelimit fix command when the parameter LAmax cannot be changed.
 15. Themethod of claim 14, further comprising acts of: comparing by opricaldrive the logical addresses (LA) of a current block with a value of theparameter LAmax stored in the address limit memory while writing in thefirst storage layer (LO); and making a transition to a first availableblock in the subsequent storage layer (LI) when a result of thecomparing act shows that the value of the parameter LAmax has beenreached for the first storage layer (LO).
 16. The method of claim 15,further comprising acts of: storing the value of the parameter LAmax inthe address limit memory of the optical drive; and writing the value ofthe parameter LAmax to a predetermined storage location of the opticaldisc.
 17. The method of claim 16, further comprising acts of: writinginformation in the logical storage space (LSS) of the optical disc;reading by the host device the value for the parameter LAmax from thepredetermined storage location; and storing by the host device the valuefor the parameter LAmax in its address limit memory.
 18. Anon-transitory computer readable medium comprising computer instructionswhich, when executed by a processor, configure the computer processor toperform a method of controlling an optical drive by a host device, theoptical drive being capable of writing information in blocks of alogical storage space (LSS) of an optical disc which has a physicalstorage space comprising two or more layers (LO; LI) of physical storagelocations, each storage location having a physical address (PA), thelogical storage space (LSS) comprising storage locations within a firststorage layer (LO) of the layers and within a subsequent storage layer(LI) of the layers, the storage locations in the logical storage space(LSS) having contiguously numbered logical addresses (LA), the methodcomprising acts of: causing the host device to provide data to theoptical drive, the data containing information to be written onto theoptical disc and/or data containing instructions for the optical drive,the optical drive having an address limit memory containing at least anindication of a parameter LAmax indicating a maximum value of thelogical addresses (LA) of the storage locations in the first storagelayer (LO); causing the host device to provide to the optical drive alimit fix command instructing the optical drive to store the indicationof the parameter LAmax as determined by the host device in the addresslimit memory; causing the optical drive to change the indication of theparameter LAmax in the address limit memory to the indication providedby the host device; causing the host device to send a Disc Read Commandto the optical drive; causing the host device to receive a Disc ReadResponse from the optical drive indicating whether or not the parameterLAmax is changeable; and causing the host device to avoid providing thelimit fix command in response to the act of receiving a Disc ReadResponse from the optical drive indicating that the parameter LAmaxcannot be changed.
 19. The non-transitory computer readable medium ofclaim 18, comprising further computer instructions which, when executedby a computer processor, configure the processor to perform acts of:causing the oprical drive to compare the logical addresses (LA) of acurrent block with a value of the parameter LAmax stored in the addresslimit memory while writing in the first storage layer (LO); and causingthe oprical drive to make a transition to a first available block in thesubsequent storage layer (LI) when a result of the comparing act showsthat the value of the parameter LAmax has been reached for the firststorage layer (LO).
 20. The non-transitory computer readable medium ofclaim 19, comprising further computer instructions which, when executedby a computer processor, configure the processor to perform acts of:causing the oprical drive to store the value of the parameter LAmax inthe address limit memory of the optical drive; and causing the opricaldrive to write the value of the parameter LAmax to a predeterminedstorage location of the optical disc.
 21. The non-transitory computerreadable medium of claim 20, comprising further computer instructionswhich, when executed by a computer processor, configure the processor toperform acts of: causing the oprical drive to write information in thelogical storage space (LSS) of the optical disc; causing the opricaldrive to read the value for the parameter LAmax from the predeterminedstorage location; and causing the oprical drive to store the value forthe parameter LAmax in its address limit memory.
 22. A non-transitorycomputer readable medium comprising computer instructions which, whenexecuted by a processor, configure the processor to perform a method ofoperating a host device for controlling an optical drive capable ofwriting information in a logical storage space (LSS) of an optical discwhich has a physical storage space comprising two or more layers (LO;LI) of physical storage locations, each storage location having aphysical address (PA), the logical storage space (LSS) comprisingstorage locations within a first one (LO) of the layers and within asubsequent one (LI) of the layers, the storage locations in the logicalstorage space (LSS) having contiguously numbered logical addresses (LA),the method comprising acts of: causing the host device to provide to theoptical drive data containing information to be written onto the opticaldisc and/or data containing instructions for the optical drive, theoptical drive having an address limit memory containing at least anindication of a parameter LAmax indicating a maximum value of thelogical addresses (LA) of the storage locations in the the first storagelayer (LO); causing the host device to determine whether the theindication of the parameter LAmax stored in the address limit memory ofthe optical drive is changeable; and causing the host device to send tothe optical drive a limit fix command instructing the optical drive tochange the indication of the parameter LAmax as determined by the hostdevice in the address limit memory based on a result of the determiningact, wherein the act of causing the host device to send is avoided inresponse to receiving from the optical drive an indication that theparameter LAmax cannot be changed.
 23. The A non-transitory computerreadable medium of claim 22, wherein the indication that the parameterLAmax cannot be changed is provided by the optical drive in a Disc ReadResponse in response to receiving a Disc Read Command from the hostdevice.
 24. A non-transitory computer readable medium comprisingcomputer instructions which, when executed by a processor, configure theprocessor to perform a method of operating an optical drive, the opticaldrive being capable of writing information in blocks of a logicalstorage space (LSS) of an optical disc which has a physical storagespace comprising two or more layers (LO; LI) of physical storagelocations, each storage location having a physical address (PA), thelogical storage space (LSS) comprising storage locations within a firststorage layer (LO) of the layers and within a subsequent storage layer(LI) of the layers, the storage locations in the logical storage space(LSS) having contiguously numbered logical addresses (LA), the methodcomprising acts of: causing the optical drive to receive data from ahost device, the data containing information to be written onto theoptical disc and/or data containing instructions for the optical drive,the optical drive having an address limit memory containing at least anindication of a parameter LAmax indicating a maximum value of thelogical addresses (LA) of the storage locations in the first storagelayer (LO); causing the optical drive to receive from the host device alimit fix command instructing the optical drive to store the indicationof the parameter LAmax as determined by the host device in the addresslimit memory; causing the optical drive to change the indication of theparameter LAmax in the address limit memory to the indication providedby the host device; causing the host device to send a Disc Read Commandto the optical drive; causing the host device to receive a Disc ReadResponse from the optical drive indicating whether or not the parameterLAmax is changeable so that the host device avoids sending the limit fixcommand when the parameter LAmax cannot be changed.
 25. Thenon-transitory computer readable medium of claim 24, comprising furthercomputer instructions which, when executed by a computer processor,configure the processor to perform acts of: causing the oprical drive tocompare the logical addresses (LA) of a current block with a value ofthe parameter LAmax stored in the address limit memory while writing inthe first storage layer (LO); and causing the oprical drive to make atransition to a first available block in the subsequent storage layer(LI) when a result of the comparing act shows that the value of theparameter LAmax has been reached for the first storage layer (LO). 26.The non-transitory computer readable medium of claim 25, comprisingfurther computer instructions which, when executed by a computerprocessor, configure the processor to perform acts of: causing theoprical drive to store the value of the parameter LAmax in the addresslimit memory of the optical drive; and causing the oprical drive towrite the value of the parameter LAmax to a predetermined storagelocation of the optical disc.
 27. The non-transitory computer readablemedium of claim 26, comprising further computer instructions which, whenexecuted by a computer processor, configure the processor to performacts of: causing the oprical drive to write information in the logicalstorage space (LSS) of the optical disc; causing the oprical drive toread the value for the parameter LAmax from the predetermined storagelocation; and causing the oprical drive to store the value for theparameter LAmax in its address limit memory.